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In 1977, the first successful coronary angioplasty was performed by Andreas Gruentzig using a double-lumen balloon catheter. This pivotal event spurred major advances in the field of percutaneous coronary intervention (PCI) over the subsequent four decades, including in the setting of myocardial infarction (MI) where primary PCI is now the established gold standard therapy. Nonetheless, although reperfusion is the cornerstone of management of acute MI, the role of various adjunctive therapies also needs to be recognized as these have had a substantial influence in improving both morbidity and mortality. This chapter serves to revisit the key historical milestones that have helped shape the modern management of acute MI.

The outcomes of patients suffering from acute myocardial infarction are contingent on the time taken to deliver definitive treatment. Evidence has shown that the extent of myocardial salvage is greatest if patients are reperfused in the first 3 h from the onset of symptoms [1]. For every 30-min delay in coronary reperfusion, the relative 1-year mortality rate increases by 7.5% [2]. This has driven physicians and policy-makers to popularize phrases such as ‘time is myocardium’ and concepts such as ‘door-to-balloon’ time—the latter representing the time to reperfusion with an intracoronary device from the arrival of the patient at hospital (Fig. 2.1). The biggest delays and challenges in reducing the time to reperfusion, however, are in fact mostly seen in the prehospital setting. This consists of the time from the onset of symptoms to first medical contact (FMC) and subsequently the time from FMC to diagnosis and then reperfusion treatment—termed ‘system delay’. Patient delay may be multifactorial and depends on a host of issues including socioeconomic factors and access to healthcare. The rapid patient assessment and field diagnosis of myocardial infarction has become a crucial factor in time to reperfusion as it dictates the decision on the most appropriate form of reperfusion treatment accounting for geographical factors and available facilities. Importantly, the prehospital role in the management of acute myocardial infarction also involves the initiation of therapy, the upstream of the hospital-delivered treatment. This commonly involves the administration of antiplatelet and anticoagulant therapy in metropolitan areas, while in remote areas where patients cannot be transferred to hospital facilities in a reasonable time, there are policies in place for administration of field thrombolytic agents. Other aspects of the management may involve intravenous access or, indeed in the cases of cardiac arrest, cardiopulmonary resuscitation. In this chapter we will discuss the management of patients presenting with acute myocardial infarction, in the crucial period ahead of their arrival at the heart attack centre.

Internationally ischaemic heart disease (IHD) is the single most common cause of death, and its frequency is increasing. The relative incidences of ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) are decreasing and increasing, respectively. In European countries, the incidence rate for STEMI ranges from 43 to 144 per 100,000 population per year. Similarly, the reported adjusted incidence rates from the USA decreased from 133 per 100,000 in 1999 to 50 per 100,000 in 2008, whereas the incidence of NSTEMI remained constant or increased slightly. STEMI is more common in younger than in older people and is more common in men than in women.

The facilities and expertise required for primary percutaneous coronary intervention (PPCI) of the infarct-related artery (IRA) in patients with ST-elevation myocardial infarction (STEMI) are only available at a limited number of hospitals. Fibrinolytic therapy, on the other hand, is more widely deliverable. This creates two distinct reperfusion choices: PPCI or a pharmacoinvasive strategy. The first option relies on immediate transfer to the closest PPCI-capable centre even if it means bypassing a closer non-PPCI centre. The second option is the “drip and ship” strategy. It involves delivery of fibrinolytic therapy by a non-PPCI facility with rapid transfer to a PPCI-capable centre.

It is estimated that there are 1.5 million hospitalizations with acute coronary syndromes (ACS) per year in the United States, with 30–45% being a ST-segment elevation myocardial infarction (STEMI) presentation [2]. STEMI occurs due to an acute occlusion of an infarct-related artery (IRA) that can cause irreversible ischemia-induced myocardial necrosis within 20–60 min of onset. Untreated STEMI patients have higher mortality and poor clinical outcomes compared to those who receive a reperfusion strategy [3–10]. The mainstay of STEMI management is rapid intervention aimed at relieving the IRA thrombotic obstruction and thus reducing infarct size, preserving left ventricular function, and decreasing morbidity and mortality. In the 1980s, fibrinolysis became the standard means to achieve reperfusion. Subsequently, a number of randomized trials and meta-analyses showed that primary PCI (PPCI), when performed rapidly, was associated with improved clinical outcomes compared to fibrinolytic therapy [11–18]. However, the mortality benefit of primary PCI is reduced with treatment delays, with no benefit observed when the difference between time of fibrinolysis and time of PCI exceeds 115 min [19, 20]. Current guidelines recommend the use of fibrinolytic therapy when the time from first medical contact to PCI is anticipated to be greater than 120 min [17, 18]. Despite these recommendations, data from the US National Cardiovascular Data Registry showed that only 51% of STEMI patients transferred for primary PCI achieved the recommended first door-to-balloon time of <120 min [21]. Similar European data show that 65% of transferred patients had a delay of >120 min, which was associated with increased mortality [22].

Treatment of acute myocardial infarction has improved dramatically in recent years. Primary percutaneous coronary intervention (PPCI) has now become the mainstay of treatment and is available to all but a few geographical catchment areas in the UK. Annually over 24,000 primary PCIs are performed in the UK representing approximately a quarter of the total coronary intervention cases each year [1].

Before cardiac catheterization, patient preparation and checking of general condition and appropriateness for procedure should be done. This may not always be possible in emergency cases however.

Platelet inhibition remains the core pharmacotherapy component in patients undergoing emergency or primary percutaneous coronary interventions (PCI). This can be achieved using a number of intravenous and oral preparations. Intravenous (iv) antiplatelets include various glycoprotein IIb/IIIa (GPIIb/IIIa) inhibitors and the only available intravenous PY inhibitor, cangrelor. Available oral agents include aspirin and various PY inhibitors or their analogues. These are usually used in combination with the intention to maintain dual antiplatelet therapy (DAPT) for a period of time (generally up to 12 months) after the index PCI procedure.

Percutaneous coronary interventions (PCI) mandate usage of anticoagulants to facilitate a successful and safe procedure. This chapter reviews commonly used anticoagulant regimens used for PCI with tailored guidance for the acute setting, in particular primary PCI for ST-elevation myocardial infarction (STEMI).

Partial or complete occlusion of the infarct-related artery (IRA) with intracoronary thrombus (ICT) is the pathognomonic hallmark of patients presenting with ST-elevation myocardial infarction (STEMI). Thrombus burden can be highly variable, but its presence is associated with worse outcomes, including lower procedural success, increased abrupt vessel closure and an increased frequency of major in-hospital complications including death and recurrent myocardial infarction (MI). ICT poses a unique series of challenges, but appropriate management is an essential prerequisite for successful primary percutaneous coronary intervention (PPCI). This can largely be achieved using a combination of pharmacological and mechanical approaches prior to coronary stent insertion.